‘Salt Pit’ Prehistoric Town in Bulgaria’s Provadiya Built Oldest Stone Fortress Walls in Europe to Protect Its Riches, Archaeologist Says

Some 6,700 years ago the residents of the Solnitsata (“The Salt Pit") prehistoric town in today’s Provadiya in Northeast Bulgaria built what were Europe’s first fortress walls made of stone in order to protect their riches accumulated from the large-scale production of salt extracted from a massive rock salt deposit.

In 2016, several roughly 6,500-year-old gold artifacts were discovered in the prehistoric Salt Pit town, together with numerous other finds, and back in September 2015, with the discovery of a 6,300-year-old gold jewel also made international headlines.

Also in September 2016, Nikolov announced the discovery of a roughly 6,400-year-old water well where the archaeological team reached water at a depth of 8 meters.

Notable also for its impressive size, the Salt Pit settlement mound in Bulgaria’s Provadiya is believed to have been the home of Europe’s richest residents in the middle of the 5th millennium BC.

The high Chalcolithic (Aeneolithic, Copper Age) civilization which inhabited today’s Bulgaria at the time is also known, among other things, for world’s oldest gold treasure, the Varna Gold Treasure, which was discovered 40 km to the east of the Salt Pit town, in the Varna Chalcolithic Necropolis near Bulgaria’s Black Sea city of Varna.

However, lead researcher Vasil Nikolov has repeatedly cautioned that at the time, in the 5th millennium BC, gold was a mere status symbol, while salt was likely more precious because it was also used as a means of exchange, i.e. a prehistoric currency of sorts.

The 2017 archaeological excavations in the Provadiya – Solnitsata Settlement Mound have provided further insight into the impressive nature of what were Europe’s first stone fortress walls.

“This is what is left of the first stone fortress in Europe, built ca. 4,700 BC, which was destroyed by an earthquake," explains the lead archaeologist.

“After that, they built a second fortress wall… the construction was sturdy but it turned out that in a very strong earthquake with an epicenter near Shabla and Kavarna (on the Black Sea coast, to the northeast – editor’s note) the first wall was demolished. After that, it took a second hit from an earthquake with an epicenter in Vrancea, Romania. Thus, the town’s first fortification system was severely damaged," Nikolov elaborates.

“However, they made their second (chronologically) fortress wall really robust," he adds.

The foundations of the very stone fortress wall of the Salt Pit town were wide between 3 and 4 meters, while the wall is estimated to have towered at a height of between 4 and 6 meters.

The scope of the fortification is taken to mean that the Provadiya – Solnitsata prehistoric settlement was constantly under threat in the 5th millennium BC.

“I cannot think of any such serious fortifications from either the Antiquity, or the Middle Ages. And this thing here was built some 4,600 BC, i.e. 6,600 years ago," Nikolov notes.

“There was nothing else of this sort in Europe at the time," the archaeologist elaborates.

During its 1,250 years of existence the Salt Pit town had three fortress walls, each an upgrade of the previous one. Photos: TV grabs from BNT

He points out that the threat for the Salt Pit town was because of its enormous richest for its time.

“It is just that these people were crazy rich. These were the richest people in Europe at the time because they were the lords of the salt. And salt was the first universal measurement," that is, a currency, he adds.

“[The residents here] were guarding the salt. People usually tend to think of gold. However, at the time signified a person’s prestige but it was not a measurement. It became such only in the 7th century BC when the first gold coins emerged. [In the 5th millennium BC,] salt is exchanged. Salt bullions, not gold bullions, mattered," the archaeologist elaborates.

He goes on to point out that many of the top elements of fortress building which are usually attributed to the Bronze Age, with the fortifications of ancient Troy as an often cited example, can actually be observed in the prehistoric town of Provadiya – Solnitsata in today’s Northeast Bulgaria but from a much earlier time.

“This is precisey where the art of constructing stone fortress walls was born. This is where the first ever idea of bastions emerged – i.e. projections of part of the wall so that the defenders can be positioned forward, get a better view, and shoot at attackers from the side," Nikolov says.

“This is what textbooks on fortress building and fortifications mention as important in terms of elements of the defensive system. It is usually mentioned with respect to the Bronze Age, and Troy is given as an example. But many of those elements emerged here," he adds.

Lead archaeologist Nikolov shows a prehistoric bastion protruding several meters ahead of the main fortress wall. The bastion is also visible in the aerial photos below. Photos: TV grabs from BNT

Bone arrow tips have been discovered all over the place as a testimony to the numerous sieges and attacks that the fortress of the Salt Pit prehistoric town.

The second fortress wall was also destroyed, and the residents of the settlement constructed a third one, which was made of massive stones.

One further fortification innovation was the construction of radial walls down the slopes of the hill of the prehistoric fortress was located. They divided the battlefield into sections and prevented the attackers from helping one another or flocking to concentrate their forces on a specific part of the wall during a siege.

“The radial walls were put up in order to impede the attackers as much as possible. Let’s imagine that the attackers are going up towards the walls, and some of them have to help others, at another section. However, in order to do that, they have climb over that wall," Nikolov explains.

The Provadiya – Solnitsata Settlement was able to last a long siege. One water well discovered by the archaeologists was built in the last phase of the existence of the fortress when the third fortress wall was constructed.

Lead archaeologist Nikolov shows ruins from radial walls that served to devide the battlefield around the fortress into isolated sections. Photo: TV grab from BNT

The Provadiya – Solnitsata was settled during the Neolithic by some of the world’s first farmers.

They came to discover and use the huge cone-shaped rock salt deposit which is now found about 13 meters under the level of the settlement mound exposed by the archaeological excavations.

The fact that rock salt all of a sudden became an extreme valued commodity in the prehistoric world is explained with the shift from hunting and gathering to agriculture.

The plant-dominated diet of the prehistoric farmers had substantially less salt compared with the diet based on hunting so humans had to find additional sources of salt.

The rock salt deposit at today’s Provadiya in Northeast Bulgaria might have been considered a pure treasure, and the local residents of the town had a sophisticated industry for extracting and processing the rock salt.

The moist salt was placed in cylindrical clay vessels and was baked. The gold bullions produced as a result were preserved and traded with.

“[They had these] facilities with four canals… ashes can be seen at the bottom. They put firewood at the bottom, and the ceramic vessels were on top. The fire vaporized the water, and only the salt remained. One such facility could produce up to 200 kilograms of salt [at a time]," the lead archaeologist explains.

As the initial extraction of salt brought riches and, respectively, power to the residents of the prehistoric town, they found a way to increase their production 100-fold by replacing the individual flat vessels they used with tall and narrow vessels.

“These were deep, conic vessels which left enough space for filling it up with firewood and maintaining a fire. There are fragments from such vessels, there are bottoms, for example, some were made on a mat because an imprint from that mat can be seen," Nikolov says.

One loading of the improved processing facility could produce some 5 metric tons of dry salt which is said to have presented enormous wealth in the 5th millennium BC.

This painting shows how conical ceramic vessels for vaporizing the moisture and producing dry salt. Photo: TV grab from BNT

A bottom fragment from one of the clay vessels with an imprint of a mat on which it was made. Photo: TV grab from BNT

Fragments from the numerous ceramic vessels used for producing dry salt. Photo: TV grab from BNT

Some 1,250 years after the extraction of rock salt began at the Provadiya – Solnitsata prehistoric town, the climate changed, the salt sources dried out, and the once vibrant prehistoric community was ripped apart by internal strife.

A mass grave discovered by the archaeologists is believed to testify to murders committed at the time. The fortress fell, and the town remained dead for the next four millennia.

The rock salt deposits at Bulgaria’s Provadiya were rediscovered by the Ancient Thracians some 4,000 years later. From the period of Ancient Thrace, the archaeologists have found the foundations of what is said to have been a royal residence.

The Provadiya – Solnitsata Settlement Mound in Northeast Bulgaria is yet to be further researched, and is believed to have a lot more exciting information to unveil about the prehistoric civilization that established Europe’s first town, and about those who came thousands of years after them.

The prehistoric well used in the final stage of existence of the Salt Pit town. The archaeologists reached water in it at a depth of 8 meters. Photos: TV grabs from BNT

The prehistoric settlement of Provadiya – Solnitsata (i.e. “The Salt Pit"), also known as the Provadiya Settlement Mound is located 6 km southeast of the modern-day town of Provadiya, VarnaDistrict, in Northeast Bulgaria. It is a prehistoric settlement mound which in a later historical period was turned into a large Ancient Thracian burial mound. It has been dubbed “Europe’s oldest prehistoric town.

The prehistoric settlement mound has an archaeological layer of about 6 meters, and a diameter of 105 meters at the only rock salt deposit in the eastern part of the Balkan Peninsula. It is has a territory of 7 decares (app. 1.75 acres).

The extraction of rock salt began during the Late Neolithic, about 5,400-5,000 BC, with the prehistoric residents of the town boiling water from a local salt water spring in ceramic vessels placed inside large domed kilns, and producing salt bricks which they traded and used for the preservation of meat.

The Salt Pit settlement near Provadiya is Europe’s earliest known case of the use of this salt-making technology making Provadiya the oldest salt producing center on the continent.

The life of the Providiya – Solnitsata settlement continued during the Mid Chalcolithic, i.e. between 4,600 and 4,500 BC, and the Late Chalcolithic, between 4,500 and 4,200 BC, when it developed further into a major salt making complex, with the initial kilns being replaced by open-air salt pits up to 10 meters in diameter.

The prehistoric people would light an open fire at the bottom of the pit to boil the salt water in large clay bowls. It is estimated that in this period the town was inhabited by about 350 people.

The Salt Pit settlement near Bulgaria’s Provadiya has yielded a number of other intriguing discoveries such as Europe’s earliest two-storey homes from the Late Neolithic which were used for both dwelling, and salt making, as well as a granary where the archaeologists have found four sicklesmade of deer horns.

The lucrative extraction and trade of rock salt are believed to have led to the accumulation of wealth by the prehistoric inhabitants of the Provadiya – Solnitsata settlement, and have been linked to the gold treasure of the Varna Chalcolithic Necropolis (4,500-4,200 BC), the oldest hoard of gold objects found in the world, which is located 37 km to the east.

The riches of the settlement had to be protected which is why during the Mid Chalcolithic its inhabitants built a fortification consisting of a moat and a rampart wall of oak poles covered with clay as well as two large-scale stone bastions.

The bastions were destroyed by an earthquake around 4,550 BC leading the prehistoric people to build new walls made of stone, which also were destroyed by an earthquake. The moat in front of the fortress walls had a diameter of about 100 meters, and was over 2 meters wide, and 3.3 meters deep.

The archaeological artifacts from the fortified prehistoric settlement Provadiya – Solnitsata are part of the collections of the National Institute and Museum of Archaeology in Sofia and Provadiya Museum of History.